Press for dental flasks



March 21, 1950 E. LEVINSOHN ET AL 2,501,527

PRESS FOR DENTAL /FLASKS Filed March 22, 1946 41 7 V J H P 1011 1215 B BM A A TTORNE Y.

Patented Mar. 21, 1950 PRESS FOR DENTAL FLASKS Erwin Levinsohn, Englewood, N. J and Vincent A, Belanger, Brockton, Mass.

Application March 22, 1946, Serial N0.-656,340

4 Claims. (Cl. 18-5.7)

This invention relates to the presses employed by dentists and dental technicians for pressing towards each other the sections of a dental flask containing moldable material to force such material into every part of the mold in which it is to be hardened or vulcanized as by the application of heat. The material must be forced by such a firm steady pressure into every small recess in a mold in a flask but so as not to break or injure the material of the mold, and also to permit the material which is squeezed out from between the mold sections to be trimmed off.

The purpose of this device is to provide a press in which the pressure can be applied with relative slowness and care but in which the pressure can be instantly released allowing the movable member to spring back out of the way as quickly as possible so that the thin web which usually forms between the flat parts of the flask members can be trimmed off and pressure again applied and the same process gone over a second or a third time if necessary.

As these molds are more or less fragile, the pressure must be carefully applied but the release can be instantaneous.

With some types of screw presses now extensively in use, the dental technician does not bother to hold or fasten the flask together, after it is ready to be put in boiling hot water, but takes the whole press and throws it in. This procedure often requires several presses where one would be enough, it wears out the press very' rapidly because of rust and the press must be carefully wiped to remove the water.

The feature of our device is the provision of a stand with a base from which a plurality of guide posts extend upward to support and hold a top from which, usually extending downwardly, there extends an hydraulic jack of any-of the well known types, the power for which is pro vided by a manually operable handle, although it might be operated by power, and having a quick release valve by which it can quickly be released, the hydraulic jack being carried by its piston which is fixed to the top plate with its cylinder extending downwardly.

This cylinder carries at its bottom end a pressure plate both the cylinder and the pressure plate being slidable up and down towards the base of the stand. This pressure plate has a plurality of guide or post holes through each of which a post extends from the base to the top of the stand whereby the pressure plate with its cylinder can be guided in its up and down movements.

There are also returning springs, one

around each guide post between the pressure plate and the stand base, so that when the release valve is opened, these springs return the parts to their normal position, out of engagement with the flask, which can be quickly re-,

moved and replaced by another.

In the drawings, Fig. 1 is an isometric view of the complete device with a flask in position.

Fig. 2 is a sectional view showing particularly the jack, piston, the pump head, and the'valve' connections in the pressure plate.

Fig. 3 is a diagrammatic front elevational view showing a different arrangement of the various parts with the springs and pressure plate at thetop instead of at the bottom.

In the drawings is shown a stand which includes a base B which can rest upon a table M as shown and a top plate T which are connected by a plurality of connecting guide posts P, P, P, P.

Carried by this stand is a hydraulic jack J which includes a piston D which extends through top plate T and is held thereon by the nuts I and 2. This piston has a head 3 slidable on the inside of a cylinder C which carries at its bottom the pressure plate A. Through pressure plate A are the four guide post holes such as 4, 4, through one'of which each guide post P passes, so that the whole hydraulic jack J can slide up and. down. a

' This jack as shown includes an outside jacket 5 for cylinder C which creates a liquid reservoir E and this reservoir is connected with cylinder C by inlet passages l0 and II in which there is any common type of valve such as [2 and I3 together with a handle H, attached by a link [4 to any part of the jack J and which'operates a pump piston I5 in a well known manner to serve as a force pump to draw liquid from the reservoir E and to force it into the cylinder C back of the piston head 3 thereby to force the cylinder C and pressureplate A down upon a dental flask such as F or any well known type. I To raise the jack including the cylinder reser' voir, handle and other parts, we provide compression springs such as S, S, each of which passes around a post P between plate A and base B so that they tend to lift the jack with its handle and other parts while the operation of the handle H causes them tO'be forced downward against the flask.

We show also a release valve V with a handle R to control the outlet passages l5 and II from, the cylinder C to the reservoir E.

it will therefore be seen that by turning handle R of the valve V the springs S, S are allowed to operate to lift the jack assembly very quickly thus permitting the dental flask F to be removed and replaced by another with very little loss of time and with no moving of the device.

The jack assembly is substantially the same as one shown in patent to Dybens, Re. No. 16,900 of March 13, 19.28., but the inlet and outlet valves could be varied in many ways and the reservoir E instead of being concentric with cylinder (I could be a separate non-concentric container.

As shown in Fig. 3, the base B of, the stand. can be connected with a top plate T by guide posts P and jack J can rest" on base B, or base B might be its own base. In such case the handle H and valve V of jack J will; be in the. same position near the bottom as in the first described construction but instead of the piston D being attached to the top plate T, it can be directly L attached to a pressure plate such as A which isslidable on posts such as P or thepiston and pressure plate need not be fastened together.

In any case, a dental flask such as F is pressed v between the top plate T and pressure plate A and by means of t'he'handle H the-pressure plate is forced against it and held. there as long as necessary and then by opening release valve V the pressure is released.

In=thiscase the compression springs suchas S each surrounds a post P and are positioned between the top plate T and the pressure plate A so that when valve V is opened, they force pressure plate A away'from top plate T thus releasing the pressure in the flask F between them so, that it can be removed or replaced by another.

Wezclaim:

1. .In a press for dental flasks, the combination of a stand including a base, a top plate and a plurality: of connecting guide posts between them; with an hydraulic jack including a cylinder carrying a concentric liquid reservoin. a pressure plate slidable on said posts between the baseand thetop plate, a piston attached to the top plate. of the. stand; a pressure pump. operableby apivoted. handle for: pumping liquid from the reservoir into and for producing hydraulic pressurein thexcylind'er, and a manually operablerelease valve between the cylinder and the; reservoir torelease; the liquid" and the hydraulic pressure in; the cylinder; and compression springs each pass? ing: around a. guide; post between the pressure plate, andthe-base to return the hydraulic jack, cylinder and; pressure plate .to their normal positions;

2; In a press for dental'flasks, the combination of.-a stand includinga base, a top plate and a. pluralityof connecting. guide posts between them; with apressure plate slidable on said DOStSibE- tween. the; base andthe, top plate; a hydraulic jack. positioned between the base and. the pros sure-plate, said jackincluding a liquid reservoir, a-,cylinder, apiston. a pressure: pump operableby a pivoted handle, for: pumping.-liquid'; from the reservoir into and for producing hydraulic; presi sure in the cylinder and a manually operable release valve between the cylinder and the reservoir to release the liquid and the hydraulic pressure in the cylinder; and compression springs each passing around a guide post, to return the hydraulic jack, and pressure plate to their normal positions when the release valve is opened.

3. In a press for dental flasks, the combination ot a. stand including a base, a t'ep'plate and a plurality of connecting guidepo'sts between them;

, with an hydraulic jack including a cylinder carrying a concentric liquid reservoir, 3. pressure plate: slidable on said posts between the base and the top plate, a piston attached to the top plate ofthe. stand, a pressure pump operable by a pivoted handle, and including inlet passages with aone. way valve system, for pumping liquid from the reservoir into and for roducing hydraulic pressure in the cylinder, and a manually operable release valve in an outlet passage between the. cylinder and the reservoir to release the liquid and the hydraulic pressure in the cylir'ider; and compression-springs each passing around a guide post between the pressure plate and the base to return the hydraulic jack, cylinder and pressure plate to their normal positions, and to return the hydraulic 1 jack operating liquid from the cylinder to: the. reservoir.

4-. In a press for dental flasks, the combination of a standiincluding a base, a top plate and a plurality of; connecting guide posts between them; with a. pressure? plate slidable on said posts between the. base and the top plate; a hydraulic jack positioned between the base and the' pres sure. plate; saidf jack: including a liquid reservoir,

a cylinder, a. piston, a; pressure pump op'erable by a: pivoted handle, and including. inlet passages with a; one way valve system, for pumping liquid from the reservoir into andv for producing hydraulic: pressurein" the cylinder and amanually oper able: release valve: in an outlet passage between-'- the cylinder and the reservoir to release: the liduid and. the hydraulic. pressure: in the cylinder; and compression springs each' passing aroundvaf .guide post, to return the hydraulic jack, and

pressure plateto' their normal positions: when the release: valve is; opened and to return: the hydrau' lie: ask operating liquid from. the cylinder to the: reservoir.

ERLWIN LEVINSOHN-Z' VINCENT A. BELANGER.

REFEfiENCE'S- CITED' The following references are of record in the file of" this patent:

UNITED STAT-ES- PATENTS- Number Name Date 566,207 Mignault Aug. .18, 139 6 718,286 Smith Jan. 13, 19 03 1,610,499 Dybens Dec; I4, 1926 1,823,213 Schmidt Sept. 15, 1931 11,952,951 Stahley- Mar. 27, 193 4 2,072,694 Walter Mar. 2; 1 9 37" 

